It is not merely an inconvenience to deal with bad actors-there are some other good reasons to get rid of them.

Breeding Herd

A recent report from Florida (Cooke et al., 2009) investigated reproductive performance in pasture-mated cows based on a combined docility score. The scores were an average among those for reaction when in a chute, in a pen, and a measured exit velocity when released from the chute. Combined with plasma cortisol levels (a measure of animal stress), these workers found a negative relationship between the combined docility score and reproductive performance.

Several purebred cattle organizations have used a docility score (a score ranging from 1 to 6 with 1 being very docile to 6 being very aggressive) to predict docility in progeny through the generation of expected progeny differences for the trait. The heritability is moderate to high for docility (0.37 in the American Angus Association database), which means significant progress can be made in improving the trait through selection for more docile cattle. Specific genes related to docility have been identified in cattle, and the presence of these genes can be determined in the laboratory by commercial companies that provide this service for this and many other traits.

Feedlot Cattle

Most of the data available related to the influence of docility is with feedlot cattle. Table 1 shows the results of docility on feedlot performance and carcass traits for over 13,000 cattle fed in southwestern Iowa during 2002-2004. These data clearly show docility can have a significant effect on the economics of feeding cattle.

Table 1. Docility Score and Feedlot Performance, 2002-2004

Item

Docile

Restless

Aggressive

Busby, D., 2009.

% of total cattle

72.4

21.8

5.8

Overall ADG

3.17

3.11

2.91

Feed/Gain

7.10

7.13

7.23

Morbidity rate (%)

19.2

16.8

16.2

Mortality rate (%)

1.09

1.02

1.91

% prime

1.7

1.2

0.1

% choice

72.4

67.9

58.1

% select

23.3

27.5

36.2

% standard

2.6

3.4

5.6

On a choice/select spread of just $6.00/cwt, these results indicate the value of docile compared to aggressive cattle would be about $67.00 per steer, and this does not include the extra feed, time in the feedlot, and added treatment cost and death rate of aggressive cattle. Additionally, another study (Berg, et al, 2009) indicated cattle with a higher exit velocity after release from a chute had significantly higher toughness in their steaks based on Warner-Bratzler shear values. A 1997 study in Colorado (Voisinet et al.) showed average daily gain of feedlot cattle was reduced by 0.4 lbs/day in English and continental breeds and by 0.6 lbs./day in Brahman and Brahman-cross cattle when temperament scores ranged from calm to continuous movement in a chute.

Culling Based on Docility

Most small-herd cattle managers are aware of the cattle with bad behavior in their herds. There is evidence these cattle should be culled from the breeding herd because they will have both lower reproductive performance, and there is a fairly high probability their offspring will have similar behavior problems. Cattle feeders should critically evaluate docility in cattle at arrival and after 30 days in the feedlot. Studies show that some cattle that arrive under stress at the feedlot will overcome the behavior problem after acclimation. However, if bad behavior persists, there are two major reasons to remove these cattle from the pen. First, their individual performance and carcass values will be reduced. Secondly, unpublished work at Penn State with small pens of cattle indicated those cattle with poor behavior tended to influence bad behavior in their penmates as well. Cattle in pasture programs will usually elicit increased behavior problems because of fewer interactions with humans. Frustration in moving cattle and fixing fences will become a problem!

We always knew we did not like to deal with bad actors. Here is the evidence to get rid of them and do yourself a favor in many ways.